Effect of Arc Column Voltage on the Current Limiting Performance in Moulded Case Circuit Breaker

From traditional point of view,it is consideration that the current limiting performance of molded case circuit breaker(MCCB) depend on the electrode fall voltage due to the quenching method in low-voltage circuit breaker to be based on splitting the arc into a series of short arcs by deion plate.According to the compact geometry along with limited number of deion plates of MCCB,it was proposed that arc column voltage also play an important role in interrupting process of MCCB.In order to clarify the contribution of arc column voltage,the empirical expression of arc voltage for MCCB was used to make analysis,and the arc voltage was measured for with and without deion plates.The experiment to make comparison between repulsion only in movable contact side and both in movable and fixed contact sides was carried out,the latter has high current limiting feature,because elongation of the arc length causes the arc column voltage increase.